by Cameron Crooks
Published Friday, March 27, 2026.
Introduction
Tool use has been a subject of large amounts of literature from archaeologists and primatologists who recognize the advancement in tool technology in relation to changes in cognitive skill and dietary behavior. Previously, Leakey et al. connected manual abilities to tool use as a crucial part of the definition for genus Homo (Leakey et al., 1964). This belief became entrenched in human evolutionary studies, and it was long assumed that the genus Homo must have been connected to the emergence of stone tool production (Harris 1983). When Leakey discovered fossils in association with stone tools at Olduvai Gorge in Tanzania in 1964, they were quickly assigned to the new species Homo habilis, the “handy man.” The tool use, therefore, became a fundamental part of the modern human lineage’s success. However, the recent discovery of the new Lomekwian tools at Lomekwi 3, dating to 3.3 Mya, almost half a million years before the earliest fossil evidence of Homo, and the confirmation of cutmarked bones at Dikika dated to 3.4 Mya have complicated the connection between lithic technology and the genus Homo (Harmand et al. 2015; Lewis and Harmand 2016; McPherron et al. 2010; Thompson et al. 2015; Villmoare et al. 2015).
Due to bias in preservation in the archaeological record, the study of hominin material culture is often heavily biased towards lithic technology. However, new developments in primate archaeology and new analytical techniques in hand morphology are rapidly challenging the importance of focusing solely on stone tool use. Multiple recent studies have found that “all modern nonindustrialized human societies as well as non-human primate species use plant materials for implements far more often than bones or stone” (Carvalho and Almeida-Warren 2019; Gonzalez-Ruibal, Hernando, and Politis 2011; Hoffecker and Hoffecker 2018; Pascual-Garrido and Almeida-Warren 2021). The proposed study of the “archaeology of the perishable” from Pascual-Garrido and Almeida-Warren provides a crucial framework for reconstructing technologies invisible in the archaeological record through analysis of living ape behavior (Pascual-Garrido and Almeida-Warren 2021).
Finally, new developments in analytical techniques within paleoanthropology are rapidly increasing our understanding of the tool-use capability of hominins. The growing body of literature analyzing hand morphology has proven to be contradictory and full of debate (Almecija and Alba 2014; Skinner et al. 2015; Pickering et al. 2018; Mongle et al. 2025). This paper will attempt to mediate between these opposing views and analyze hand morphology based on the available archaeological and behavioral evidence. Each of these lines of evidence will be used to evaluate the evidence of tool usage within populations before the genus Homo. By utilizing this interdisciplinary approach from multiple fields, I hope to challenge pre-existing narratives on tool usage and its connection to the genus Homo as a result of the newest evidence.
Pre-Industry and Early Lomekwian Tools
The recent discovery of pre-Oldowan industry dating to before the genus Homo fundamentally challenges the previous assumption that members of the genus Homo were the only individuals engaging in lithic technology. The stone tools found at Lomekwi 3 are significantly larger in length, width, and thickness than the Oldowan tool (Harmand 2015). The artifacts were most likely used as part of a hammer-on-anvil technique similar to that of chimpanzees and capuchins when cracking nuts (Sakura and Matsuzawa 1991; Visalberghi et al. 2013). This is vastly different from the freehand percussion associated with the Oldowan industry (Harmand 2015). Furthermore, the diversity of dimensions and features suggests that users were handling the artifacts in a way that suggests technological diversity fundamentally different from uni-purpose primate tools (Carvalho et al. 2008; Harmand 2015; Marchant and McGrew 2005)
The Lomekwian tools predate the oldest fossils of the genus Homo, found in the form of the Ledi-Geraru mandible at 2.8 Mya, by almost half a million years (Villmoare et al. 2015). The only specimen found in the same chronological and geographical context as the Lomekwian tools is Kenyanthropus platyops, also found in West Turkana (Leakey et al. 2001). However, in the Lower Awash Valley, there are Australopithecus afarensis specimens found in association with cut-marked bones from Dikika 3.39 Mya (McPherron et al. 2010; Thompson et al. 2015).
The lack of Kenyanthropus platyops hand fossils for morphometric analysis makes it difficult to know for certain if they had the hand motor control necessary to create the Lomekwian tools. To create the tools found at Lomekwi 3, a hominin would have required substantial hand motor control and reorganization of several regions of the cerebral cortex (Harmand et al. 2015). The cut-marks associated with Au. afarensis would seem to make this species a good candidate for possible users of Lomekwian tools, however, the hand morphology evidence proves to be complex and contradictory.
Au. afarensis hand morphology has been complicated by the large amount of fossils and morphological diversity, combined with the relatively low amount of complete metacarpals that can be reliably attributed to the same individual. Recent studies have found that Au. afarensis had a manipulation workspace similar to modern humans based on their joint mobility and proportions critical for precision grip and manipulation potential (Alba et al. 2003; Feix et al. 2015; Marzke 1997). Hand proportions for Au. afarensis have been estimated to have a very wide range as a result of the morphological diversity, with some researchers finding them gorilla-like and some finding them similar to humans ( Alba et al. 2003; Almecija and Alba 2014; Rolian and Gordon 2013). Rolian and Gordon suggest that Au. afarensis did not have the capability for precision grips of the same efficiency as modern humans, while Alba et al. suggest that they did have the human-like pad-to-pad precision grip (Alba et al. 2003, Kivell 2015, Rolian and Gordon 2013).
Generally, based on the hand morphology analysis of Au. afarensis, it seems that the species had both modern human hand traits and primitive hand traits that would have weakened its precision grip to a lesser capability than that of modern humans. This is to be expected from a species this far back in the human evolutionary lineage; however, this also provides evidence that Au. afarensis might have been using Lomekwian tools. There are significant accidents in the knapping process observed during flaking in stones at Lomweki 3 (Lewis and Harmand 2016). One possible cause of this is that the hominin knappers were physically less capable of striking accurately to remove flakes at the correct angle. In addition to the cut marks from Dikika, the evidence of early primitive Lomekwian tools and Au. afarensis hand morphology suggests that Australopithecines could engage in the lithic industry.
In light of the hand morphology evidence, it is logical that Australopithecines could have also engaged in using organic material for tool production that would not survive in the archaeological record. In addition to the hand morphology evidence, the recent lithic finds have created a paradigm shift in paleoanthropology that shows the ability of Australopithecines to use tools (Lewis and Harmand 2016). This necessitates questioning the Australopithecines’ ability to use organic tools from plants as well, due to the unlikelihood of these human ancestors overlooking the value of organic materials as tools (Conard et al. 2015; Dominguez-Rodrigo et al. 2001; Panger et al. 2002).
Pascual-Garrido and Almeida-Warren argue that a vital component of tool use is the transport of materials (Pascual-Garrido and Almeida-Warren 2021). Based on tool usage from chimpanzees, they argue that chimpanzees are set apart from other nonhuman tool manufacturers in their flexible use of diverse implements more similar to humans (McGrew 1992; McGrew et al. 2019; Pascual-Garrido and Almeida-Warren 2021; Rolian and Carvalho 2017). Based on studies of wild chimpanzees, Pascual-Garrido and Almeida-Warren believe that the behaviors archaeologists reconstructed associated with Oldowan industry are similar to the organic tools used by wild chimpanzees, and therefore would have been present in the last human-chimpanzee common ancestor (McGrew 2010; Pascual-Garrido and Almeida-Warren 2021). If all the behaviors associated with Oldowan can be associated with chimpanzees, this means it is logical that those further back in our evolutionary lineage were certainly using perishable tools beyond 3.3 Mya, as associated with the Lomwekian tools. Despite the lack of archaeological evidence due to the tools’ perishability, it is possible that other members of the Australopithecines with the hand morphology for tool usage could have engaged in using perishable tools around the same period the Lomwekian tools were found.
When discovered by Raymond Dart in 1957, Australopithecus africanus was thought to have a connection with osteodontokeratic tool usage that we now know to be a false connection (Randolph-Quinney and Sinclair 2022). Since Au. africanus has not been found associated with stone tools or cut-marks on bone at this time, hand morphology serves as the best indicator of possible tool usage. Pickering et al. argue that the hands of Au. africanus at Sterkfontein have hand morphology that “lacks complete modern humanlike manual dexterity” (Pickering et al. 2018). However, Skinner et al. suggest that Au. africanus has a trabecular structure similar to Neandertals and H. sapiens that would have allowed for “forceful opposition of the thumb and fingers during human-like precision and power grips” (Skinner et al. 2015). Furthermore, it has been demonstrated that forces on the thumb are highest when using precision grip flaking instead of early stone tool making (Panger et al. 2002; Williams et al. 2012). Based on the combined hand morphology studies, it would seem that Au. africanus had powerful human-like grips, but may have lacked complete human-like dexterity, which supplies further evidence that Au. africanus may have been capable of primitive tool use. Since the Lomekwian tools were created in East Africa using a primitive, inaccurate flaking method at roughly the same time period (3.3 Mya), it is possible that Au. africanus was also capable of creating a primitive tool culture that may not have survived in the archaeological record or a stone tool technology that has simply not been uncovered yet in South Africa (Lewis and Harmand 2016).
If we accept, as proposed by Pascual-Garrido and Almeida-Warren, that the LCA between humans and chimpanzees used perishable tools, then it is likely that Au. africanus could have had the same type of tool usage. The counterargument to this is the low amount of tool usage seen in wild gorilla populations, implying that this skill was perhaps lost over their lineage (Pascual-Garrido and Almeida-Warren 2021). Recent research in primate behavior has shown that the difference in nonhuman primate tool use could be related to diet flexibility (Masi 2023. Bonobos and gorillas both have a high diet flexibility, meaning that they have more options when fruit is scarce. Chimpanzees, on the other hand, have a higher necessity for high-quality foods, which could be related to their higher rates of tool usage (Masi 2023). Therefore, tool use is hypothesized to be connected to food scarcity in the current debate on primate tool use (Masi 2023).
Isotope studies of Au. Africanus has highlighted that the species was highly opportunistic and had a generalist diet similar to that of modern gorillas, which do not exhibit high levels of tool use due to the lack of food scarcity they face (van der Merwe et al. 2003). Based on this evidence, it is logical that Au. africanus would not have stone tools associated with its chronology or geography since there may not have been enough food scarcity to push them into requiring tool usage. However, it is important to recognize that their hand morphology represents the distinct possibility of low levels of perishable tool use similar to that of gorillas. Au. sediba is much more similar to chimpanzees in its diet, and consumed a large amount of C3 despite the widely available C4 (Henry et al. 2012). In addition, Au sediba’s hand morphology contains both trabecular morphology consistent with orangutans and power-grasping, as well as human-like thumbs for mechanical manipulation (Dunmore et al. 2020). Since the paleoenvironment was predominantly C4, it is likely that Au. sediba faced food scarcity to maintain its preference for a C3 diet. The hand morphology and diet suggest that it is likely that Au sediba could have engaged in using perishable archaeology to maintain this diet, similarly to our most prolific modern nonhuman primate tool users, the chimpanzees.
Oldowan Tool Industry
The earliest Oldowan tools at 3 to 2.6 Mya predate the earliest fossil attributed to Homo at 2.8 Mya by nearly 200,000 years (Plummer et al. 2023; Semaw et al. 1997; Roche and Tiercelin 1977; Villmoare et al. 2015). Originally, the Oldowan tool industry was predominantly assigned to the genus Homo as its primary creators. However, the increasing evidence of Oldowan tools found in association with members of the genera Australopithecus and Paranthropus seems to highlight a more complex history behind Oldowan technology.
Australopithecus garhi fossils have been found close to faunal remains with butcher marks indicating stone tool use, and occur during the temporal range for Oldowan tools (Williams et al. 2025; Heinzelin et al. 1999). However, new evidence has suggested that these butcher marks could have also been evidence of crocodile trampling, making it difficult to confirm Au. garhi’s connection to Oldowan tool use (Sahle et al. 2017; Williams et al. 2025).
New research has suggested that the genus Paranthropus was associated with Oldowan tools from its onset due to the increasingly significant amount of sites connecting them (Prat 2023; Plummer et al. 2023). The discovery of two hippopotamid butchery sites associated with C4 grazing fauna and the first Paranthropus sp. teeth in southwestern Kenya has shown diets high in C4 foods (Plummer et al. 2023). Paranthropus molar KNM-NG 77316, attributed to P. boisei, was found in clear association with stone artifacts (Plummer et al. 2023). These new findings suggest that early Oldowan was more widespread than previously thought, and could have been a vital part of processing megafuna used in the diet of Paranthropus.
Paranthropus robustus specifically has been found in association with butchered fossil remains in Member 3 at Swartkrans, which has been argued to be evidence of P. robustus’s association with the stone tools found in Member 5 at Sterkfontein (Hanon et al. 2025). According to Hanon and associates, it seems likely that the Acheulean stone tools found in Member 5 are attributed to Homo ergaster remains, while the Oldowan tools are likely associated with P. robustus based on the butchery marks (Hanon et al. 2025). This new evidence challenges the assumption that Homo was the only species capable of tool use, as there seems to have been contemporaneous tool usage of more primitive technology by Paranthropus.
After the discovery of H. habilis, Paranthropus boisei was quickly forgotten as a possible tool user (Leakey et al. 1964; Prat 2023). New emerging evidence complicates this original interpretation and raises the possibility that P. boisei is a highly likely tool user. The P. boisei molar KNM-NG 77316 at Nyayanga is associated clearly with Oldowan artifacts in situ where no early Homo remains have been found (Plummer et al. 2023). The closest early Homo remains for this time period are found at Ledi Geraru, over 1300 kilometers away (Villmoare et al. 2015). According to a review of Oldowan assemblages and P. boisei remains, Prat finds that many authors are hesitant to accept P. boisei as potential toolmakers, but that there is a significant association between Oldowan sites and P. boisei remains that is not negligible. In addition, recent findings from Williams and colleagues agree with this analysis by showing that P. boisei and H. habilis are the early hominins most frequently associated with Oldowan, and arguing that P. boisei is the “principal Oldowan toolmaker after the emergence of the Acheulean” (Williams et al. 2025).This analysis is supported by the newest research revealing P. boisei’s hand morphology. Mongle and colleagues found that the hand morphology of KNM-ER 101000 was capable of tool making, but is also similar to gorilla morphology associated with processing and climbing (Mongle et al. 2025). With associated stone tools and the hand morphology capable of tool usage, P. boisei are likely to have engaged in creating Oldowan stone tools. This finding fundamentally challenges previous assumptions about the use of tools and their isolation to the genus Homo by showing that multiple genera before Homo were likely to have engaged in tool use.
Conclusion
This research proposes serious questions about the validity of tool use and its connection to the genus Homo. In addition, this calls into question some of the proposed definitions used to set Homo habilis as part of the genus Homo when it was labeled the “handyman” in relation to tool usage. As new discoveries continue to push back the date for the stone tool industry and hand morphology suitable for tool use, it is vital to adapt to new research and question previous assumptions about Australopithecus and Paranthropus.
Often, the material record will not show the complete story of hominin evolution. Therefore, it is important to continue to combine new analytical approaches using isotope analysis and hand morphology alongside modern primate archaeology and studies on animal behavior. By drawing from multiple disciplines, it is possible to paint a clearer picture of human evolution.
